public async Task <BoolResult> OnChangeCheckpointAsync(OperationContext context, CheckpointState initialState, CheckpointManifest manifest)
{
_activeCheckpointInfo = _activeCheckpointInfo with
{
Manifest = manifest
};
if (initialState.FileName == null)
{
return(BoolResult.Success);
}
return(await context.PerformOperationAsync(
Tracer,
async() =>
{
var(state, index) = await _storage.ReadModifyWriteAsync <CheckpointState, int>(context, initialState.FileName.Value, state =>
{
var index = state.Consumers.Count;
var updated = state.Consumers.TryAdd(_primaryMachineLocation);
if (!updated)
{
index = state.Consumers.IndexOf(_primaryMachineLocation);
}
return (state, index, updated);
},
defaultValue: () => initialState).ThrowIfFailureAsync();
var locations = GetCandidateLocations(state, index);
_activeCheckpointInfo = new CheckpointInfoSnapshot(manifest, locations);
return Result.Success(index);
},
public record CheckpointInfoSnapshot(CheckpointManifest Manifest, IReadOnlyList <MachineLocation> Locations);
